Sensor system

ABSTRACT

A first light emitting element emits first detecting light toward the outside of a vehicle. A second light emitting element emits second detecting light toward the outside of the vehicle. A first light receiving element outputs a first signal corresponding to an amount of incident light. A second light receiving element outputs a second signal corresponding to an amount of incident light. A processor acquires first data corresponding to the first signal and second data corresponding to the second signal, and exchanges the first data and the second data in a case where the first data is based on the second detecting light and the second data is based on the first detecting light.

FIELD

The presently disclosed subject matter relates to a sensor systemadapted to be installed in a vehicle.

BACKGROUND

In order to realize the driving support technology of the vehicle, asensor for detecting information in an outside area of the vehicle shallbe mounted on the vehicle body. Examples of such sensors include LiDAR(Light Detection and Ranging) sensors and cameras (see, e.g., PatentDocument 1).

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Publication No. 2010-185769 A

SUMMARY Technical Problem

In the sensor system as described above, it is demanded to suppressdegradation in the information acquisition capability caused byvibration or the like of the vehicle.

Solution to Problem

In order to meet the demand described above, a first illustrative aspectof the presently disclosed subject matter provides a sensor systemadapted to be installed in a vehicle, comprising:

a first light emitting element configured to emit first detecting lighttoward the outside of the vehicle;

a second light emitting element configured to emit second detectinglight toward the outside of the vehicle;

a first light receiving element configured to output a first signalcorresponding to an amount of incident light;

a second light receiving element configured to output a second signalcorresponding to an amount of incident light; and

a processor configured to acquire first data corresponding to the firstsignal and second data corresponding to the second signal, andconfigured to exchange the first data and the second data in a casewhere the first data is based on the second detecting light and thesecond data is based on the first detecting light.

According to such a configuration, even when reflected light from anexternal object is not normally incident on the light receiving elementdue to vibration or the like of the vehicle, it is possible to outputdata corresponding to a normal light receiving state. Accordingly, in asensor system including at least two sets of light emitting elements andlight receiving elements, it is possible to suppress degradation ininformation processing capability caused by vibration or the like of thevehicle.

The sensor system according to the first illustrative aspect may beconfigured to comprise:

a third light emitting element disposed between the first light emittingelement and the second light emitting element, and configured to emitthird detecting light toward the outside of the vehicle; and

a third light receiving element disposed between the first lightreceiving element and the second light receiving element, and configuredto output a third signal corresponding to an amount of incident light,

wherein the processor is configured to acquire third data correspondingto the third signal, and configured to create average data by subjectingthe first data and the second data to averaging processing to exchangethe third data with the average data in a case where both of the firstdata and the third data are based on the first detecting light or thethird detecting light, or a case where both of the second data and thethird data are based on the second detecting light or the thirddetecting light.

According to such a configuration, even when reflected light from anexternal object is not normally incident on the light receiving elementdue to vibration or the like of the vehicle, it is possible to outputdata similar to the data that shall be obtained in the normal lightreceiving state. Accordingly, in a sensor system including at leastthree sets of light emitting elements and light receiving elements, itis possible to suppress degradation in information processing capabilitycaused by vibration or the like of the vehicle.

The sensor system according to the first illustrative aspect may beconfigured such that the first light receiving element and the secondlight receiving element are arranged in a direction corresponding to anup-down direction of the vehicle.

The vibration of the vehicle is dominated by a component in the up-downdirection. Accordingly, the abnormal light reception described above islikely to occur between the first light receiving element and the secondlight receiving element arranged in the direction corresponding to theup-down direction of the vehicle. However, since the processor canperform the above-described exchange or averaging processing of thefirst data and the second data, it is possible to effectively correctthe influence of the inversion phenomenon in the light reception causedby the vibration of the vehicle.

The sensor system according to the first illustrative aspect may beconfigured such that the first light emitting element, the second lightemitting element, the first light receiving element, and the secondlight receiving element constitute a part of at least one of a LiDARsensor unit, a TOF camera unit, and a millimeter wave radar unit.

In order to meet the demand described above, a second illustrativeaspect of the presently disclosed subject matter provides a sensorsystem adapted to be installed in a vehicle, comprising:

a sensor unit configured to detect information in an outside area of thevehicle;

a displacement sensor configured to detect displacement of the sensorunit in a direction along at least an up-down direction of the vehicle;and

a processor configured to correct data corresponding to the informationon the basis of data corresponding to the displacement.

According to the configuration as described above, it is possible tosuppress the influence of the displacement of the sensor unit caused bythe vibration or the like of the vehicle on the information detection.Accordingly, it is possible to suppress degradation in the informationacquisition capability of the sensor system caused by vibration or thelike of the vehicle.

The sensor system according to the second illustrative aspect may beconfigured such that the sensor unit is at least one of a LiDAR sensorunit, a TOF camera unit, and a millimeter wave radar unit.

As used herein, the term “sensor unit” means a constituent unit of acomponent that can be distributed by itself as a single unit whileproviding a desired information detecting function.

As used herein, the term “driving support” means control processing thatat least partially performs at least one of driving operation (steeringoperation, acceleration, deceleration), monitoring of a drivingenvironment, and backup of driving operation. That is, it includes notonly the partial driving support such as braking function for collisionavoidance and assisting function for lane-keeping, but also a fullself-driving operation.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates a functional configuration of a sensor systemaccording to a first embodiment.

FIG. 2A is a diagram for explaining how the sensor system of FIG. 1operates.

FIG. 2B is a diagram for explaining how the sensor system of FIG. 1operates.

FIG. 3 illustrates an operation flow of the sensor system of FIG. 1.

FIG. 4 illustrates another exemplary configuration of the sensor systemof FIG. 1.

FIG. 5A is a diagram for explaining how the sensor system of FIG. 4operates.

FIG. 5B is a diagram for explaining how the sensor system of FIG. 4operates.

FIG. 6 illustrates a functional configuration of a sensor systemaccording to a second embodiment.

FIG. 7A is a diagram for explaining how the sensor system of FIG. 6operates.

FIG. 7B is a diagram for explaining how the sensor system of FIG. 6operates.

DESCRIPTION OF EMBODIMENTS

Examples of embodiments will be described below in detail with referenceto the accompanying drawings. In each of the drawings used in thefollowing description, the scale is appropriately changed in order tomake each member have a recognizable size.

FIG. 1 illustrates a configuration of a sensor system 1 according to afirst embodiment. The sensor system 1 is installed in a vehicle.

The sensor system 1 includes a LiDAR sensor unit 10. The LiDAR sensorunit 10 includes a first light emitting element 111, a second lightemitting element 112, a first light receiving element 121, and a secondlight receiving element 122.

The first light emitting element 111 is configured to emit firstdetecting light L11 toward the outside of the vehicle. The firstdetecting light L11 is non-visible light. As the non-visible light, forexample, infrared light having a wavelength of 905 nm can be used. Asthe first light emitting element 111, a semiconductor light emittingelement such as a laser diode or a light emitting diode can be used.

The second light emitting element 112 is configured to emit seconddetecting light L12 toward the outside of the vehicle. The seconddetecting light L12 is non-visible light. As the non-visible light, forexample, infrared light having a wavelength of 905 nm can be used. Asthe second light emitting element 112, a semiconductor light emittingelement such as a laser diode or a light emitting diode can be used.

The first light receiving element 121 is configured to output a lightreceiving signal S21 corresponding to the amount of incident light. Thefirst light receiving signal S21 is an example of the first signal. Thefirst light receiving element 121 has sensitivity to at least thewavelength of the first detecting light L11. As the first lightreceiving element 121, a photodiode, a phototransistor, a photoresistor, or the like can be used.

The second light receiving element 122 is configured to output a lightreceiving signal S22 corresponding to the amount of incident light. Thesecond light receiving signal S22 is an example of the second signal.The second light receiving element 122 has sensitivity to at least thewavelength of the second detecting light L12. As the second lightreceiving element 122, a photodiode, a phototransistor, a photoresistor, or the like can be used.

The sensor system 1 includes a control device 20. The control device 20includes an input interface 21, a processor 22, an output interface 23,and a communication bus 24. The input interface 21, the processor 22,and the output interface 23 can exchange signals and data via thecommunication bus 24.

The first light receiving signal S21 outputted from the first lightreceiving element 121 and the second light receiving signal S22outputted from the second light receiving element 122 are inputted tothe input interface 21.

The processor 22 acquires the first data D1 and the second data D2respectively corresponding to the first light receiving signal S21 andthe second light receiving signal S22 that are inputted to the inputinterface 21. The first data D1 and the second data D2 are placed in astate that can be subjected to information processing performed in theprocessor 22 (described later). That is, the input interface 21 has anappropriate circuit configuration for converting the first lightreceiving signal S21 and the second light receiving signal S22 into thefirst data D1 and the second data D2, respectively.

The processor 22 inputs the first control signal S11 to the first lightemitting element 111 via the output interface 23, thereby controllingthe light emitting operation of the first light emitting element 111.Specifically, the amount of light, the light emission timing, the lightemission cycle, and the like of the first detecting light L11 arecontrolled. By appropriately performing adjustment of the light emittingtiming or light modulation, identification information can be assignedto the first detecting light L11.

Similarly, the processor 22 inputs the second control signal S12 to thesecond light emitting element 112 via the output interface 23, therebycontrolling the light emitting operation of the second light emittingelement 112. Specifically, the amount of light, the light emissiontiming, the light emission cycle, and the like of the second detectinglight L12 are controlled. By appropriately performing adjustment of thelight emitting timing or light modulation, identification informationcan be assigned to the second detecting light L12.

As illustrated in FIG. 2A, the first detecting light L11 emitted fromthe first light emitting element 111 is reflected by an object thatsituates outside the vehicle, so that first reflected light L21 isgenerated. The identification information assigned to the firstdetecting light L11 is reflected to the first reflected light L21. Thefirst reflected light L21 is incident on the first light receivingelement 121. The first light receiving element 121 outputs a first lightreceiving signal S21 corresponding to the amount of the first reflectedlight L21. As a result, the first data D1 associated with the firstreflected light L21 is obtained. The identification information assignedto the first detecting light L11 is also reflected to the first data D1.

Similarly, the second detecting light L12 emitted from the second lightemitting element 112 is reflected by an object that situates outside thevehicle, so that second reflected light L22 is generated. Theidentification information assigned to the second detecting light L12 isreflected to the second reflected light L22. The second reflected lightL22 is incident on the second light receiving element 122. The secondlight receiving element 122 outputs a second light receiving signal S22corresponding to the amount of the second reflected light L22. As aresult, the second data D2 associated with the second reflected lightL22 is obtained. The identification information assigned to the seconddetecting light L12 is also reflected to the second data D2.

The processor 22 can obtain the distance to the object associated withthe first reflected light L21 based on the time period from the timewhen the first detecting light L11 is emitted to the time when the firstreflected light L21 is detected. Additionally or alternatively, theprocessor 22 can obtain information as to an attribute such as thematerial of the object associated with the first reflected light L21based on the difference in waveforms of the first detecting light L11and the first reflected light L21.

Similarly, the processor 22 can obtain the distance to the objectassociated with the second reflected light L22 based on the time periodfrom the time when the second detecting light L12 is emitted to the timewhen the second reflected light L22 is detected. Additionally oralternatively, the processor 22 can obtain information as to anattribute such as the material of the object associated with the secondreflected light L22 based on the difference in waveforms of the seconddetecting light L12 and the second reflected light L22.

As illustrated in FIG. 1, the LiDAR sensor unit 10 may include ascanning mechanism 13. The scanning mechanism 13 changes the lightemitting directions of the first detecting light L11 and the seconddetecting light L12 along a direction S intersecting the arrangementdirection of the first light emitting element 111 and the second lightemitting element 112. The processor 22 can control the operation of thescanning mechanism 13 via the output interface 23.

N sets of first data D1 and second data D2 are acquired by repeating thelight emitting operation and the light receiving operation N timesduring a single scanning. For example, by acquiring the distanceinformation to the object described above for the N sets of data, it ispossible to acquire information as to the shape of the object associatedwith the first reflected light L21 and the second reflected light L22.

The processor 22 is configured to output data DO including theinformation of the object that situates outside the vehicle acquired asdescribed above via the output interface 23 to an external entity. Thedata DO is used for additional information processing performed byanother processor.

FIG. 3 illustrates a flow of processing performed by the processor 22.First, the processor 22 acquires the first data D1 and the second dataD2 as described above (STEP1).

Subsequently, the processor 22 determines whether or not there is aninversion phenomenon of light reception (STEP2). Specifically, it isdetermined whether the first data D1 is based on the first detectinglight L11. Similarly, it is determined whether the second data D2 isbased on the second detecting light L12.

As described with reference to FIG. 2A, in the normal state, the firstreflected light

L21 generated by the first detecting light L11 is incident on the firstlight receiving element 121, and the second reflected light L22generated by the second detecting light L12 is incident on the secondlight receiving element 122. Accordingly, if the first data D1 iscreated on the basis of the first reflected light L21, theidentification information assigned to the first detecting light L11 isreflected in the first data D1. If the second data D2 is created on thebasis of the second reflected light L22, the identification informationassigned to the first detecting light L11 is reflected in the seconddata D2. The processor 22 makes the above-described determinationthrough the detection of the identification information.

When it is determined that the first data D1 is based on the firstdetecting light L11 and the second data D2 is based on the seconddetecting light L12 (N in STEP2 of FIG. 3), the first data D1 and thesecond data D2 are outputted as they are as illustrated in FIG. 2A(STEP3 of FIG. 3). Thereafter, the processing returns to STEP1.

As illustrated in FIG. 2B, when the LiDAR sensor unit 10 is displaceddue to vibration or the like of the vehicle, the first reflected lightL21 may happen to be incident on the second light receiving element 122and the second reflected light L22 may happen to be incident on thefirst light receiving element 121. In this case, the identificationsignal assigned to the second detecting light L12 is reflected in thefirst data D1 created on the basis of the first light receiving signalS21 outputted from the first light receiving element 121. On the otherhand, the identification signal assigned to the first detecting lightL11 is reflected in the second data D2 created on the basis of thesecond light receiving signal S22 outputted from the second lightreceiving element 122. When the first data D1 and the second data D2 areoutputted as they are, the accuracy of the information as for the objectin an outside area of the vehicle that is to be obtained by thesubsequent processing is reduced.

Accordingly, when it is determined that the first data D1 is based onthe second detecting light L12 and the second data D2 is based on thesecond detecting light L12 (Y in STEP2 of FIG. 3), the processor 22performs processing for exchanging the first data D1 and the second dataD2, as illustrated in FIG. 2B (STEP4 of FIG. 3). Subsequently, the firstdata D1 and the second data D2 that have been exchanged are outputted(STEP3 of FIG. 3). For example, when the first data D1 and the seconddata D2 are serially outputted, the order of outputting the first dataD1 and the second data D2 is exchanged. For example, when the first dataD1 and the second data D2 are outputted in parallel, the addresses ofthe output ports assigned to both data are exchanged.

When N light emitting operations and light receiving operations areperformed during a single scanning while the light emitting directionsof the first detecting light L11 and the second detecting light L12 arechanged by the scanning mechanism 13, a data set of 2 rows×N columns (aset including N first data D1 and N second data D2) is acquired. In thiscase, the exchange of the first data D1 and the second data D2 may beperformed in units of rows. That is, the entire N pieces of first dataD1 and the entire N pieces of second data D2 can be exchanged with eachother.

According to such a configuration, even when reflected light from anobject is not normally incident on the light receiving element due tovibration or the like of the vehicle, it is possible to output datacorresponding to a normal light receiving state. In a sensor systemincluding at least two sets of light emitting elements and lightreceiving elements, it is possible to suppress degradation ininformation processing capability caused by vibration or the like of thevehicle.

In the present embodiment, the first light receiving element 121 and thesecond light receiving element 122 are arranged in a directioncorresponding to an up-down direction of the vehicle.

The vibration of the vehicle is dominated by a component in the up-downdirection. Accordingly, the above-described inversion phenomenon oflight reception is likely to occur between the first light receivingelement 121 and the second light receiving element 122 arranged in thedirection corresponding to the up-down direction of the vehicle.However, since the processor 22 can exchange the first data D1 and thesecond data D2 as described above, it is possible to effectively correctthe influence of the inversion phenomenon in the light reception causedby the vibration of the vehicle.

FIG. 4 illustrates another exemplary configuration of the sensor system1. The LiDAR sensor unit 10 according to the present example furtherincludes a third light emitting element 113 and a third light receivingelement 123.

The third light emitting element 113 is disposed between the first lightemitting element 111 and the second light emitting element 112. Thethird light emitting element 113 is configured to emit third detectinglight L13 toward the outside of the vehicle. The third detecting lightL13 is non-visible light. As the non-visible light, for example,infrared light having a wavelength of 905 nm can be used. As the thirdlight emitting element 113, a semiconductor light emitting element suchas a laser diode or a light emitting diode can be used.

The third light receiving element 123 is disposed between the firstlight receiving element 121 and the second light receiving element 122.The third light receiving element 123 is configured to output a lightreceiving signal S1 corresponding to the amount of incident light. Thethird light receiving signal S23 is an example of the third signal. Thethird light receiving element 123 has sensitivity to at least thewavelength of the third detecting light L13. As the third lightreceiving element 123, a photodiode, a phototransistor, a photoresistor, or the like can be used.

The third light receiving signal S23 outputted from the third lightreceiving element 123 is inputted to the input interface 21 of thecontrol device 20. The processor 22 acquires the third data D3corresponding to the third light receiving signal S23 inputted to theinput interface 21. The third data D3 is placed in a state that can besubjected to information processing performed in the processor 22(described later). That is, the input interface 21 has an appropriatecircuit configuration for converting the third light receiving signalS23 into the third data D3.

The processor 22 inputs the third control signal S13 to the third lightemitting element 113 via the output interface 23, thereby controllingthe light emitting operation of the third light emitting element 113.Specifically, the amount of light, the light emission timing, the lightemission cycle, and the like of the third detecting light L13 arecontrolled. By appropriately performing adjustment of the light emittingtiming or light modulation, identification information can be assignedto the third detecting light L13.

As illustrated in FIG. 5A, the third detecting light L13 emitted fromthe third light emitting element 113 is reflected by an object thatsituates outside the vehicle, so that third reflected light L23 isgenerated. The identification information assigned to the thirddetecting light L13 is reflected to the third reflected light L23. Thethird reflected light L23 is incident on the third light receivingelement 123. The third light receiving element 123 outputs a third lightreceiving signal S23 corresponding to the amount of the third reflectedlight L23. As a result, the third data D3 associated with the thirdreflected light L23 is obtained. The identification information assignedto the third detecting light L13 is also reflected to the third data D3.

The processor 22 can obtain the distance to the object associated withthe third reflected light L23 based on the time period from the timewhen the third detecting light L13 is emitted to the time when the thirdreflected light L23 is detected. Additionally or alternatively, theprocessor 22 can obtain information as to an attribute such as thematerial of the object associated with the third reflected light L23based on the difference in waveforms of the third detecting light L13and the third reflected light L23.

As illustrated in FIG. 4, the LiDAR sensor unit 10 may include ascanning mechanism 13. The scanning mechanism 13 changes the lightemitting directions of the first detecting light L11, the seconddetecting light L12, and the third detecting light L3 along a directionS intersecting the arrangement direction of the first light emittingelement 111, the second light emitting element 112, and the third lightemitting element 113. The processor 22 can control the operation of thescanning mechanism 13 via the output interface 23.

N sets of first data D1, second data D2, and third data D3 are acquiredby repeating the light emitting operation and the light receivingoperation N times during a single scanning. For example, by acquiringthe distance information to the object described above for the N sets ofdata, it is possible to acquire information as to the shape of theobject associated with the first reflected light L21, the secondreflected light L22, and the third reflected light L23.

The processor 22 is configured to output data DO including theinformation of the object that situates outside the vehicle acquired asdescribed above via the output interface 23 to an external entity. Thedata DO is used for additional information processing performed byanother processor.

The operations performed by the processor 22 according to the presentexample can also be described in the flowchart illustrated in FIG. 3.First, the processor 22 acquires the first data D1, the second data D2,and the third data D3 as described above (STEP1).

Subsequently, the processor 22 determines whether or not there is aninversion phenomenon of light reception (STEP2). The determination ismade between the first data D1 and the third data D3, as well as betweenthe third data D3 and the second data D2. For example, when it isdetermined that the first data D1 is based on the third detecting lightL13 and the third data D3 is based on the first detecting light L11 (Yin STEP2), the first data D1 and the third data D3 are exchanged(STEP4).

In this example, when it is determined that no inversion phenomenon isoccurred in the light reception (N in STEP2), it is determined whetheror not an overlap phenomenon is occurred in the light reception (STEPS).Specifically, it is determined whether both the first data D1 and thethird data D3 are based on the first detecting light L11 or the thirddetecting light L13. Similarly, it is determined whether both the thirddata D3 and the second data D2 are based on the third detecting lightL13 or the second detecting light L12.

As described with reference to FIG. 5A, in the normal state, the firstreflected light L21 generated by the first detecting light L11 isincident on the first light receiving element 121, the second reflectedlight L22 generated by the second detecting light L12 is incident on thesecond light receiving element 122, and the third reflected light L23generated by the third detecting light L13 is incident on the thirdlight receiving element 123. Accordingly, if the first data D1 iscreated on the basis of the first reflected light L21, theidentification information assigned to the first detecting light L11 isreflected in the first data D1. If the second data D2 is created on thebasis of the second reflected light L22, the identification informationassigned to the first detecting light L11 is reflected in the seconddata D2. If the third data D3 is created on the basis of the thirdreflected light L23, the identification information assigned to thethird detecting light L13 is reflected in the third data D3. Theprocessor 22 makes the above-described determination through thedetection of the identification information.

When it is determined that the first data D1 is based on the firstdetecting light L11, the second data D2 is based on the second detectinglight L12, and the third data D3 is based on the third detecting lightL13 (N in STEPS of FIG. 3), the first data D1, the second data D2, andthe third data D3 are outputted as they are, as illustrated in FIG. 5A(STEP3 of FIG. 3). Thereafter, the processing returns to STEP1.

As illustrated in FIG. 5B, when the LiDAR sensor unit 10 is displaceddue to vibration or the like of the vehicle, the third reflected lightL23 may happen to be incident on both the first light receiving element121 and the third light receiving element 123. In this case, theidentification signal assigned to the third detecting light L13 isreflected in the first data D1 created on the basis of the first lightreceiving signal S21 outputted from the first light receiving element121. Similarly, the identification signal assigned to the thirddetecting light L13 is also reflected in the third data D3 created onthe basis of the third light receiving signal S23 outputted from thethird light receiving element 123. When the first data D1 and the thirddata D3 are outputted as they are, the accuracy of the information asfor the object in an outside area of the vehicle that is to be obtainedby the subsequent processing is reduced.

Accordingly, when it is determined that both the first data D1 and thethird data D3 are based on the first detecting light L11 or the thirddetecting light L13, or when it is determined that both the second dataD2 and the third data D3 are based on the second detecting light L12 thethird detecting light L13 (Y in STEPS of FIG. 3), the processor 22performs processing for replacing the third data D3 with average dataDA, as illustrated in FIG. 5B (STEP6 of FIG. 3). The average data DA iscreated by averaging the first data D1 and the second data D2.

If only one set of the first data D1, the second data D2, and the thirddata D3 are acquired, the averaging processing is processing forcalculating a simple average of the first data D1 and the second dataD2. In a case where a plurality of sets of the first data D1, the seconddata D2, and the third data D3 are acquired by using the scanningmechanism 13, the averaging processing may be any of calculation of asimple average, calculation of a median value, and calculation of a modevalue.

Subsequently, the replaced first data D1, the second data D2, and theaverage data DA are outputted (STEP3 of FIG. 3).

According to such a configuration, even when reflected light from anobject is not normally incident on the light receiving element due tovibration or the like of the vehicle, it is possible to output datasimilar to the data that shall be obtained in the normal light receivingstate. Accordingly, in a sensor system including at least three sets oflight emitting elements and light receiving elements, it is possible tosuppress degradation in information processing capability caused byvibration or the like of the vehicle.

In the present embodiment, the first light receiving element 121, thesecond light receiving element 122, and the third light receivingelement 123 are arranged in a direction corresponding to the up-downdirection of the vehicle.

The vibration of the vehicle is dominated by a component in the up-downdirection. Accordingly, the above-described overlap phenomenon of lightreception is likely to occur among the first light receiving element121, the second light receiving element 122, and the third lightreceiving element 123 arranged in the direction corresponding to theup-down direction of the vehicle. However, since the processor 22 canperform the above-described averaging processing, it is possible toeffectively correct the influence of the inversion phenomenon in thelight reception caused by the vibration of the vehicle.

The functions of the processor 22 described later may be realized by ageneral-purpose microprocessor cooperating with a memory, or may berealized by a dedicated integrated circuit such as a microcontroller, anFPGA, and an ASIC.

The control device 20 may be disposed at any position in the vehicle.The control device 20 may be implemented by a main ECU configured toperform central control processing in the vehicle, or may be implementedby a sub ECU interposed between the main ECU and the LiDAR sensor unit10.

The above embodiments are mere examples for facilitating understandingof the presently disclosed subject matter. The configuration accordingto the above embodiment can be appropriately modified without departingfrom the gist of the presently disclosed subject matter.

In the above embodiment, the first light emitting element 111 and thesecond light emitting element 112 are arranged in the directioncorresponding to the up-down direction of the vehicle. The first lightreceiving element 121 and the second light receiving element 122 arealso arranged in the direction corresponding to the up-down direction ofthe vehicle. However, the first light emitting element 111 and thesecond light emitting element 112 may be arranged in a directioncorresponding to a left-right direction or a front-rear direction of thevehicle. The first light receiving element 121 and the second lightreceiving element 122 may also be arranged in the directioncorresponding to the left-right direction or the front-rear direction ofthe vehicle. In this case, the light emitting directions of the firstdetecting light L11 and the second detecting light L12 can be changed bythe scanning mechanism 13 in the direction corresponding to the up-downdirection of the vehicle.

The LiDAR sensor unit 10 may be replaced with an appropriate sensor unitcapable of detecting information in an outside area of the vehicle usinga light emitting element and a light receiving element. Examples of sucha sensor unit may include a TOF camera unit and a millimeter wave radarunit. A configuration using plural types of measurement techniques maybe incorporated in a single sensor unit. The wavelength of the detectinglight emitted by the light emitting element and the wavelength at whichthe light receiving element has sensitivity can be appropriatelydetermined according to the detection technique to be used.

FIG. 6 schematically illustrates a configuration of a sensor system 2according to a second embodiment. The sensor system 2 is installed in avehicle.

The sensor system 2 includes a LiDAR sensor unit 30. The LiDAR sensor 30includes a light emitting element 31 and a light receiving element 32.

The light emitting element 31 is configured to emit detecting light L1toward the outside of the vehicle. The detecting light L1 is non-visiblelight. As the non-visible light, for example, infrared light having awavelength of 905 nm can be used. As the light emitting element 31, asemiconductor light emitting element such as a laser diode or a lightemitting diode can be used.

The light receiving element 32 is configured to output a light receivingsignal S1 corresponding to the amount of incident light. The lightreceiving element 32 has sensitivity to at least the wavelength of thedetecting light L1. As the light receiving element 32, a photodiode, aphototransistor, a photo resistor, or the like can be used.

The sensor system 2 includes a control device 40. The control device 40includes an input interface 41, a processor 42, an output interface 43,and a communication bus 44. The input interface 41, the processor 42,and the output interface 43 can exchange signals and data via thecommunication bus 44.

The light receiving signal S1 outputted from the light receiving element32 is inputted to the input interface 41. The processor 42 acquireslight receiving data D11 corresponding to the light reception signal S1inputted to the input interface 41. The light receiving data D11 isplaced in a state that can be subjected to information processingperformed in the processor 42 (described later). That is, the inputinterface 41 has an appropriate circuit configuration for converting thelight receiving signal S1 into the light receiving data D11.

The processor 42 inputs a control signal SO to the light emittingelement 31 via the output interface 43, thereby controlling the lightemitting operation of the light emitting element 31. Specifically, theamount of light, the light emission timing, the light emission cycle,and the like of the detecting light L1 are controlled.

The detecting light L1 emitted from the light emitting element 31 isreflected by an object that situates outside the vehicle, so thatreflected light L2 is generated. The reflected light L2 is incident onthe light receiving element 32. The light receiving element 32 outputs alight receiving signal S1 corresponding to the amount of light of thereflected light L2. As a result, the light receiving data D11 associatedwith the reflected light L2 is obtained. The light receiving data D11 isan example of data corresponding to information in an outside area ofthe vehicle.

The processor 42 can obtain the distance to the object associated withthe reflected light L2 based on the time period from the time when thedetecting light L1 is emitted to the time when the reflected light L2 isdetected. Additionally or alternatively, the processor 130 can obtaininformation as to an attribute such as the material of the objectassociated with the reflected light L2 based on the difference inwaveforms of the detecting light L1 and the reflected light L2.

The LiDAR sensor unit 30 may include a scanning mechanism 33. Thescanning mechanism 33 changes the light emitting direction of thedetecting light L1, for example, along a direction S intersecting theup-down direction of the vehicle. The processor 42 can control theoperation of the scanning mechanism 33 via the output interface 43.

N first data D1 are acquired by repeating the light emitting operationand the light receiving operation N times during a single scanning. Forexample, by acquiring the distance information to the object describedabove for the N data sets, it is possible to acquire information as tothe shape of the object associated with the reflected light L2.

The processor 42 is configured to output data D10 including theinformation of the object that situates outside the vehicle acquired asdescribed above via the output interface 43 to an external entity. Thedata D10 is used for additional information processing performed byanother processor.

The sensor system 2 includes a displacement sensor 50. The displacementsensor 50 is configured to detect the displacement of the LiDAR sensorunit 30. The displacement sensor 50 may be implemented by anacceleration sensor or a gyro sensor. The displacement sensor 50 isconfigured to output a displacement signal S2 corresponding to thedetected LiDAR sensor unit 30.

The displacement signal S2 outputted from the displacement sensor 50 isinputted to the input interface 41 of the control device 40. Theprocessor 42 acquires displacement data D12 corresponding to thedisplacement signal S2 inputted to the input interface 41. Thedisplacement data D12 is placed in a state that can be subjected toinformation processing performed in the processor 42 (described later).That is, the input interface 41 has an appropriate circuit configurationfor converting the displacement signal S2 into the displacement dataD12.

An area A1 illustrated in FIG. 7A illustrates an information detectablearea of the LiDAR sensor unit 30. The area A2 represents an areaincluding information outputted as the above-described data D10. Theprocessor 42 extracts a portion corresponding to the area A2 from theacquired light receiving data D11 to create the data D10.

Due to vibration of the vehicle or the like, the LiDAR sensor unit 30may be displaced from the initial position indicated by dashed lines. Inthe example illustrated in FIG. 7B, the LiDAR sensor unit 30 isdisplaced in the upper right direction, and the area A1 is alsodisplaced in the upper right direction. As a result, the position of theobject to be detected moves in the left-lower direction within the areaA2. If no countermeasure is taken, there would be a case whereinformation such as the distance to the object cannot be accuratelyobtained.

The displacement of the LiDAR sensor unit 30 is detected by thedisplacement sensor 50. Based on the displacement data D12 correspondingto the displacement, the processor 42 changes the area A2 to a positionwhere the displacement of the LiDAR sensor unit 30 can be compensatedfor. In the example illustrated in FIG. 7B, the area A2 is moved fromthe initial position indicated by solid lines to the correction positionindicated by chain lines. Such a changing processing is an example ofcorrection of the light receiving data D11 based on the displacementdata D12. The D10 is created from the light receiving data D11corresponding to the area A2 the position of which has been changed inthis manner, and outputted through the output interface 43.

According to the configuration as described above, it is possible tosuppress the influence of the displacement of the LiDAR sensor unit 30caused by the vibration or the like of the vehicle on the informationdetection. Accordingly, it is possible to suppress degradation in theinformation acquisition capability of the sensor system 2 caused byvibration or the like of the vehicle.

The functions of the processor 42 described later may be realized by ageneral-purpose microprocessor cooperating with a memory, or may berealized by a dedicated integrated circuit such as a microcontroller, anFPGA, and an ASIC.

The control device 40 may be disposed at any position in the vehicle.The control device 40 may be implemented by a main ECU configured toperform central control processing in the vehicle, or may be implementedby a sub ECU interposed between the main ECU and the LiDAR sensor unit30.

The above embodiments are mere examples for facilitating understandingof the presently disclosed subject matter. The configuration accordingto the above embodiment can be appropriately modified without departingfrom the gist of the presently disclosed subject matter.

The displacement direction of the LiDAR sensor unit 30 detectable by thedisplacement sensor 50 is appropriately determined so as to include apitch direction, a yaw direction, a roll direction, a horizontal shiftdirection, and a vertical shift direction. Since the vibration of thevehicle is dominated by a component in the up-down direction, it ispreferable that the displacement sensor 50 is configured to be capableof detecting the displacement of the LiDAR sensor unit 30 at least alongthe up-down direction of the vehicle.

The LiDAR sensor unit 30 may be replaced with an appropriate sensor unitcapable of detecting information in an outside area of the vehicle usinga light emitting element and a light receiving element. Examples of sucha sensor unit may include a TOF camera unit and a millimeter wave radarunit. A configuration using plural types of measurement techniques maybe incorporated in a single sensor unit. The wavelength of the detectinglight emitted by the light emitting element and the wavelength at whichthe light receiving element has sensitivity can be appropriatelydetermined according to the detection technique to be used.

The present application is based on Japanese Patent Application No.2018-139517 filed on Jul. 25, 2018, the entire contents of which areincorporated herein by reference.

1. A sensor system adapted to be installed in a vehicle, comprising: afirst light emitting element configured to emit first detecting lighttoward the outside of the vehicle; a second light emitting elementconfigured to emit second detecting light toward the outside of thevehicle; a first light receiving element configured to output a firstsignal corresponding to an amount of incident light; a second lightreceiving element configured to output a second signal corresponding toan amount of incident light; and a processor configured to acquire firstdata corresponding to the first signal and second data corresponding tothe second signal, and configured to exchange the first data and thesecond data in a case where the first data is based on the seconddetecting light and the second data is based on the first detectinglight.
 2. The sensor system according to claim 1, comprising: a thirdlight emitting element disposed between the first light emitting elementand the second light emitting element, and configured to emit thirddetecting light toward the outside of the vehicle; and a third lightreceiving element disposed between the first light receiving element andthe second light receiving element, and configured to output a thirdsignal corresponding to an amount of incident light, wherein theprocessor is configured to acquire third data corresponding to the thirdsignal, and configured to create average data by subjecting the firstdata and the second data to averaging processing to exchange the thirddata with the average data in a case where both of the first data andthe third data are based on the first detecting light or the thirddetecting light, or a case where both of the second data and the thirddata are based on the second detecting light or the third detectinglight.
 3. The sensor system according to claim 1, wherein the firstlight receiving element and the second light receiving element arearranged in a direction corresponding to an up-down direction of thevehicle.
 4. The sensor system according to claim 1, wherein the firstlight emitting element, the second light emitting element, the firstlight receiving element, and the second light receiving elementconstitute a part of at least one of a LiDAR sensor unit, a TOF cameraunit, and a millimeter wave radar unit.
 5. A sensor system adapted to beinstalled in a sensor system, comprising: a sensor unit configured todetect information in an outside area of the vehicle; a displacementsensor configured to detect displacement of the sensor unit in adirection along at least an up-down direction of the vehicle; and aprocessor configured to correct data corresponding to the information onthe basis of data corresponding to the displacement.
 6. The sensorsystem according to claim 5, wherein the sensor unit is at least one ofa LiDAR sensor unit, a TOF camera unit, and a millimeter wave radarunit.